• Transactions of Materials Processing
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• v.33 no.3
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• pp.185-192
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• 2024

This study examined how varying tempering temperatures affect the susceptibility of Cr-Mo low alloy steels to hydrogen embrittlement. A slow strain-rate test (SSRT) was carried out on the steels electrochemically pre-charged with hydrogen in order to examine the hydrogen embrittlement behavior. The results showed that the hydrogen embrittlement resistance of the Cr-Mo low alloy steels improved with increasing tempering temperature. Thermal desorption analysis (TDA) revealed that diffusible hydrogen content decreased with increasing tempering temperature, accompanied by a slight increase in the peak temperature. This decrease in hydrogen content was likely due to a reduction in dislocation density which served as reversible hydrogen trap sites. These findings underline the significant role of tempering temperature in enhancing the hydrogen embrittlement resistance of Cr-Mo low alloy steels.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.1066-1070
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• 2003

Recently technologies have created new principle and theory but the PID control system remains its popularity as the PID controller contains simple structure, including maintenance and parameter adjustment being so simple. Thus, this paper proposes auto tune PID by fuzzy logic controller based on FPGA which to achieve real time and small size circuit board. The digital PID controller design to consist of analog to digital converter which use chip TDA8763AM/3 (10 bit high-speed low power ADC), digital to analog converter which use two chip DAC08 (8 bit digital to analog converters) and fuzzy logic tune digital PID processor embedded on chip FPGA XC2S50-5tq-144. The digital PID processor was designed by fundamental PID equation which architectures including multiplier, adder, subtracter and some other logic gate. The fuzzy logic tune digital PID was designed by look up table (LUT) method which data storage into ROM refer from trial and error process. The digital PID processor verified behavior by the application program ModelSimXE. The result of simulation when input is units step and vary controller gain ($K_p$, $K_i$ and $K_d$) are similarity with theory of PID and maximum execution time is 150 ns/action at frequency are 30 MHz. The fuzzy logic tune digital PID controller based on FPGA was verified by control model of level control system which can control level into model are correctly and rapidly. Finally, this design use small size circuit board and very faster than computer and microcontroller.

• Journal of Korean Society of Transportation
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• v.35 no.1
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• pp.37-49
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• 2017

This study proposes an analysis methodology for air quality improvement effect of transport and environment policy that are used for mobile pollution sources. The methodology considers the changes of traffic of road transport sources and air pollutant emission, the changes of atmospheric dispersion of air pollutants and the effects on the health of local residents in response to policy implementation. Especially, the changes to traffic flow must be considered in evaluating the effects on atmospheric environment as it has a direct connection to the effects of the policy in this study. We used bottom-up approach (BUA) based on the travel demand model to reflect the changes of travel behavior in detail in response to the policy implementation compared to the top-down approach (TDA) when calculating the changes of emission level of road transport. We showed the applicability of the proposed analysis methodology through a policy scenario analysis, and the analysis method can be effectively applied to the cases in which travelers' behavior changes are expected.

• Analytical Science and Technology
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• v.14 no.3
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• pp.253-258
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• 2001

This is a research on hazardous characteristics and potentials of bottom ash from 9 municipal solid waste combustors(200 tons/day) of Korea by the test methods of leaching and content. The leaching method was performed by Waste Test Method of Korea. In case of the content method, mercury was determined by thermal decomposition amalgamation atomic absorption spectrometer, other 9 elemets including Pb, which were pretreated by U.S.EPA SW-846 3050B method, were determined by flame atomic absorption spectrometer(FAAS) or inductively coupled plasma atomic emission spectrometer(ICP-AES). Results of leaching test showed that Pb and Cu was main pollutants. It was interested that the distribution rate of metals' contents of each combustors was similar and the rank of concentration was Fe>Zn>Cu>Mn>Pb>Cr>As>Cd>Hg.

• Journal of the Korean Society of Food Science and Nutrition
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• v.23 no.3
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• pp.502-508
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• 1994

A total of 24 specimens of the pufferfish, Fugu xanthopterus, purchased at a fixhmarket in Pusan, korea were examined for toxicity using the assay method of tetrodotoxin (TTX). Also, the toxins isolated from the puffer liver were partially purified and analyzed for their chemical composition by instrumental behaviors. On the whole, when the level of toxicity in each organ was analyzed compared to that of liver, they were 100 % of the lover, 92 % for the intestine, 75% for the skin, 17% for the muscle, 785 for the testis, 87% for the ovary, and 71% for bile. The highest and average scores of toxicity for the liver were 917 and $231{\pm}51MU/g$ liver, respectively. The toxins of the puffer gave four peaks in HPLC whose retention times (10, 20, 22 and 25 min) were close to those of TDA, TTX, 4-epi-TTX, and and -TTX, respectively.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.28 no.5
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• pp.533-538
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• 1995

Ten specimens of the imported pufferfish, fugu flavidus ('Sarnchaebog'), from China were assayed for anatomical distribution of toxicity, Also, a toxic ovary of each specimen was excised, and transferred into Bio-gel P-2 column chromatography for purification of the toxins. The average toxicity of all specimens assayed was calculated to be $4.1\pm 0.5\;in\;liver,\;2.8\pm1.1\;intestine,\;0.8\pm0.5\;skin,\;2.3\pm1.5\;testis\;39.0\pm16.0\;ovary\;and\;7.0\pm2.0 MU/g$ bile, respectively; Ovary was weakly toxic, but others were non-toxic or weakly toxic. Moreover, instrumental analyses including thin layer chromatography(TLC) and electrophoresis disclosed tetrodotoxin (TTX) and anhydro tetrodotoxin (anh-TTX), respectively. The toxins of the ovary gave four peaks in high performance liquid chromatography (HPLC) whose retention times (14 and 24 min) were close to those of TTX and anh-TTX, respectively.

• Journal of Korean Society of Transportation
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• v.29 no.5
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• pp.55-65
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• 2011

In effort to estimate sustainability of the transportation sector, this study conducts a comparative analysis of methodology suggested for measuring greenhouse gas emission. There are two approaches proposed by the UN IPCC: 1) top-down approach (TDA) based on the amount oil sales, and 2) bottom-up approach (BUA) utilizing the velocity of moving source and traffic volume data. The subject areas for analysis were selected based on research results by the Korea Transportation Institute that evaluate traffic sustainability of each local government. Gwacheon-si being one of the top ranked areas in sustainability, and Anseong-si being ranked at the 7th level were analyzed. By the tier 1 methodology, Gwacheon-si and Anseong-si are estimated to create 74,813ton/yr, and 584,125ton/yr of the greenhouse gas emission, respectively. The tier 3 methodology, however, estimates Gwacheon-si and Anseong-si to create 91,462ton/yr, and 163,801ton/yr of the emission, respectively. Comparison of the two estimated emissions shows considerable differences; i.e., the tier 3 method over estimates Gwacheon-si's emission by 22.3% whereas it underestimates Anseong-si's greenhouse gas emission by the factor of about 3.5 compared to the emissions obtained from the tier 1 method. The result from this study implies that the traffic-sustainability-index based grade of each local government can be evaluated differently by the method adopted for measuring greenhouse gas emission.

• FLOWER RESEARCH JOURNAL
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• v.17 no.1
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• pp.23-28
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• 2009

This study was conducted to examine the effect of plant growth regulators on the formation of adventitious bud callus(ABC) and plant regeneration in shoot tip culture of Zantedeschia spp. 'Florex Gold'. Treatment of $0.1mgL^{-1}\;N$-phenyl-N'-1,2,3-thiadiazol-5-ylurea(thidiazuron, TDZ) was more promotive for formation of ABC in shoot tip culture than 6-benzylaminopurine(BA) treatment, and short shoots were developed. Comparing to treatment of BA, mixing treatment of BA and 1-naphthaleneacetic acid(NAA) inhibited the formation of ABC and multiple shoot. The proliferation of ABC derived from sections(0.3 cm) of ABC produced by shoot tip culture in medium supplemented with $0.1mgL^{-1}\;TDZ$ was more effective in medium with $0.1mgL^{-1}\;TDZ$ or $2.0mgL^{-1}\;BA$ than the other treatments. The shoot regeneration and growth from sections of ABC was more promotive in treatment of $0.001mgL^{-1}\;TDZ$. Also, the root growth from sections of ABC was better in medium with $0.001mgL^{-1}\;TDZ$ or $0.2mgL^{-1}\;BA$. Consequently, in vitro mass production of Zantedeschia spp. 'Florex Gold' can be obtained via indirect organogenesis through plant regeneration and proliferation of ABC which was derived from shoot tip culture at $0.1mgL^{-1}\;TDZ$.

• Journal of the Korean Society for Marine Environment & Energy
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• v.13 no.4
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• pp.335-340
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• 2010

The paper describes the objectives of Yellow Sea Large Marine Ecosystem (YSLME) project, focusing on procedural and practical aspects. YSLME is a highly productive sea yet possibly one of the most impacted large marine ecosystems, in terms of anthropogenic stressors, due the enormous coastal population. The aim of the YSLME project is the reduction of ecosystem stress through identification of the environmental problems in the Transboundary Diagnostic Analysis (TDA) that are then addressed in the Strategic Action Programme (SAP). One of the major problems found to be affecting biological diversity is habitat modification through wetland reclamation, conversion and degradation. Since the early 1900's more than 40% of intertidal wetlands have been reclaimed in Korea, and 60% of Chinese coastal wetlands have been converted or reclaimed. Damaging fishing practices, pollution and coastal eutrophication have further degraded the coastal environment reducing the biological diversity. To combat this loss, the YSLME project has mounted a public awareness campaign to raise environmental consciousness targeted at all different levels of society, from politicians at parliamentary workshops, local government officer training events, scientific conferences and involvement of scientists in the project research and reporting, to university and high school students in our visiting internship programmes and environmental camps. We have also built networks through the Yellow Sea Partnership and by liaising and working with other environmental organizations and NGOs. NGO's are recognised as important partners in the environmental conservation as they already have extensive local networks that can be lacking in international organisations. Effective links have been built with many of these NGOs through the small grants programme. Working with WWF's YSESP project and other academic and research institutions we have conducted our own biodiversity assessments that have contributed to the science-based development of the SAP for the YSLME. Our regional targets for biodiversity outlined in the SAP include: Improvements in the densities, distributions and genetic diversity of current populations of all living organisms including endangered and endemic species; Maintenance of habitats according to standards and regulations of 2007; and a reduction in the risk of introduced species. Endorsement of the SAP and its successful implementation, during the proposed second phase of the YSLEM project, will ensure that biological diversity is here to benefit future generations.

• Korean Journal of Organic Agriculture
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• v.15 no.1
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• pp.59-69
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• 2007

This experiment was conducted to study the spring productivity and feeding value of hairy vetch varieties. We also measured DM yield and feeding value by analyze CP and CF that authors made possible to calculate TDN and RFV. The results can be summarized as follows; Dry matter yield were increased earlier autumn seeding date and later cut in spring. Differences of dry matter yield in earlier cut in spring was high in order of Ostsaat, Welta, Vv4712, Penn-02, Common and Minnie. Crude protein(CP) yield was increased when earlier autumn seeding date and later cut in spring. Total digestible nutrient(TDN) yield of hairy vetch varieties was decreased when later autumn seeding date, and was increased when later cut in spring. TDN yield was highest in Ostsaat and Welta varieties had highest dry matter yield. Acid detergent fiber(ADF) content was decreased when later autumn seeding date and was increased when later cut in spring. Neutral detergent fiber(NDF) content was decreased when later autumn seeding date. Average values for relative feed value(RFV) were 157% and 132% in both cut. It shows that a high feed value in all of hairy vetch varieties. Above all, the results presented that the optimal seeding date for cultivating hairy vetch in the central region of Korea is between the 10th to the 20th of September. Because Ostsaat and Welta had significantly high dry matter yield we expected Ostsaat and Welta have a higher wintering ability.